METHODS:AIMS:Pulmonary vein isolation (PVI) using ablation index (AI) incorporates stability, contact force (CF), time, and power. The CLOSE protocol combines AI and ≤6 mm interlesion distance. Safety concerns are raised about surround flow ablation catheters (STSF). To compare safety and effectiveness of an atrial fibrillation (AF) ablation strategy using AI vs. CLOSE protocol using STSF.,METHODS AND RESULTS:First cluster was treated using AI and second cluster using CLOSE. Procedural data, safety, and recurrence of any atrial tachycardia (AT) or AF >30 s were collected prospectively. All Classes 1c and III anti-arrhythmic drugs (AAD) were stopped after the blanking period. In total, all 215 consecutive patients [AI: 121 (paroxysmal: n = 97), CLOSE: n = 94 (paroxysmal: n = 74)] were included. Pulmonary vein isolation was reached in all in similar procedure duration (CLOSE: 107 ± 25 vs. AI: 102 ± 24 min; P = 0.1) and similar radiofrequency time (CLOSE: 36 ± 11 vs. AI: 37 ± 8 min; P = 0.4) but first pass isolation was higher in CLOSE vs. AI [left veins: 90% vs. 80%; P < 0.05 and right veins: 84% vs. 73%; P < 0.05]. Twelve-month off-AAD freedom of AF/AT was higher in CLOSE vs. AI [79% (paroxysmal: 85%) vs. 64% (paroxysmal: 68%); P < 0.05]. Only four patients (2%) without recurrence were on AAD during follow-up. Major complications were similar (CLOSE: 2.1% vs. AI: 2.5%; P = 0.87).,CONCLUSION:The CLOSE protocol is more effective than a PVI approach solely using AI, especially in paroxysmal AF. In this off-AAD study, 79% of patients were free from AF/AT during 12-month follow-up. The STSF catheter appears to be safe using conventional CLOSE targets.

METHODS:OBJECTIVE:To investigate the role of driver mechanism and the effect of electrogram dispersion-guided driver mapping and ablation in atrial fibrillation (AF) at different stages of progression.,METHODS:A total of 256 consecutive patients with AF who had undergone pulmonary vein isolation (PVI) plus driver ablation or conventional ablation were divided into three groups: paroxysmal atrial fibrillation (PAF; group A, n = 51); persistent atrial fibrillation (PsAF; group B, n = 38); and long standing-persistent atrial fibrillation (LS-PsAF; group C, n = 39). PVI was performed with the guidance of the ablation index. The electrogram dispersion was analyzed for driver mapping.,RESULTS:The most prominent driver regions were at roof (28.0%), posterior wall (17.6%), and bottom (21.3%). From patients with PAF to those with PsAF and LS-PsAF: the complexity of extra-pulmonary vein (PV) drivers including distribution, mean number, and area of dispersion region increased (P < .001). Patients who underwent driver ablation vs conventional ablation had higher procedural AF termination rate (76.6% vs 28.1%; P < .001). With AF progression, the termination rate gradually decreased from group A to group C, and the role of PVI in AF termination was also gradually weakened from group A to group C (39.6%, 7.4%, and 4.3%; P < .001) in patients with driver ablation. At the end of the follow-up, the rate of sinus rhythm maintenance was higher in patients with driver ablation than those with conventional ablation (89.1% vs 70.3%; P < .001).,CONCLUSION:The formation of extra-PV drivers provides an important mechanism for AF maintenance with their complexity increasing with AF progression. Electrogram dispersion-guided driver ablation appears to be an efficient adjunctive approach to PVI for AF treatment.

METHODS:PURPOSE:Whether or not pulmonary vein isolation (PVI) plus left atrial posterior wall isolation (PWI) using contact force (CF) sensing improves the ablation outcome for persistent atrial fibrillation (AF) is unclear. This study compared the outcome of PVI plus PWI and additional non-PV trigger ablation for persistent AF with/without CF sensing. METHODS:This retrospective cohort study analyzed 148 propensity score-matched persistent AF patients (median duration of persistent AF, 8 months (interquartile range, 3-24 months); left atrial diameter, 43 ± 7 mm) undergoing PVI plus PWI and ablation of non-PV triggers provoked by high-dose isoproterenol, including 74 with CF-sensing catheters (CF group) and 74 with conventional catheters (non-CF group). PVI plus PWI with no additional ablation but cavotricuspid isthmus ablation was performed without non-PV triggers in 48 CF patients (65%) and 54 non-CF patients (73%) (P = 0.38). In all other patients, we performed additional ablation of provoked non-PV triggers. RESULTS:The Kaplan-Meier estimate of the rate of freedom from atrial tachyarrhythmia recurrence of antiarrhythmic drugs at 12 months after the single procedure was higher in the CF group than in the non-CF group (85 vs. 70%, log-rank P = 0.030). A multivariable analysis revealed that using CF sensing and non-inducibility of AF from a non-PV trigger after PVI and PWI were significantly associated with a reduced rate of atrial tachyarrhythmia recurrence. CONCLUSIONS:Compared with non-CF sensing, PVI plus PWI and additional non-PV trigger ablation using CF-sensing catheters for persistent AF can reduce the rate of atrial tachyarrhythmia recurrence.